1. Field of the Invention
The present invention relates to an optical lens system, and more particularly to a three-piece optical lens system.
2. Description of the Prior Art
In recent years, with the popularity of the mobile phone cameras, the optical lens system has become smaller in size, and the electronic sensor of a general digital camera is typically a CCD (Charge Coupled Device) or CMOS (Complementary Metal Oxide Semiconductor) sensor. Due to advances in semiconductor manufacturing, the pixel size of sensor has been reduced continuously, and miniaturized optical lens systems have increasingly higher resolution. Therefore, there's an increasing demand for an imaging lens system with better image quality.
Conventional miniaturized lens systems mostly consist of three lens elements as shown in FIG. 3, from the object side to the image side: a first lens element 91 with positive refractive power, a second lens element 92 with negative refractive power and a third lens element 93 with positive refractive power. Such arrangements are favorable to correct various aberrations, however, the second lens element 92 is negative and the refractive power of the third lens element 93 is not big, such that the refractive power of the first lens element 91 must be big enough to provide the refractive power of the optical lens system, which will increase the sensitivity of the optical lens system and reduce the yield rate.
Therefore, the present invention is aimed at providing an optical lens system which can improve the yield rate and provide great image quality.
The present invention mitigates and/or obviates the aforementioned disadvantages.